io_uring: Fix race for sqes with userspace

io_ring_submit() finalises with
1. io_commit_sqring(), which releases sqes to the userspace
2. Then calls to io_queue_link_head(), accessing released head's sqe

Reorder them.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2019-10-25 12:31:31 +03:00 committed by Jens Axboe
parent fb5ccc9878
commit 935d1e4590

View File

@ -2795,13 +2795,14 @@ out:
submit++;
io_submit_sqe(ctx, &s, statep, &link);
}
io_commit_sqring(ctx);
if (link)
io_queue_link_head(ctx, link, &link->submit, shadow_req);
if (statep)
io_submit_state_end(statep);
io_commit_sqring(ctx);
return submit;
}